package com.github.niefy.modules.sys.oauth2;
import com.github.niefy.common.exception.RRException;

import java.security.MessageDigest;
import java.util.UUID;
/**
 * 生成token
 *
 * @author Mark sunlightcs@gmail.com
 */
public class TokenGenerator {
  private static final char[] HEX_CODE = "0123456789abcdef".toCharArray();
  public static String generateValue() {
    return generateValue(UUID.randomUUID().toString());
  }
  public static String toHexString(byte[] data) {
    if (data == null) {
      return null;
    }
    StringBuilder r = new StringBuilder(data.length * 2);
    for (byte b : data) {
      r.append(HEX_CODE[(b >> 4) & 0xF]);
      r.append(HEX_CODE[(b & 0xF)]);
    }
    return r.toString();
  }
  public static String generateValue(String param) {
    try {
      MessageDigest algorithm = MessageDigest.getInstance("MD5");
      algorithm.reset();
      algorithm.update(param.getBytes());
      byte[] messageDigest = algorithm.digest();
      return toHexString(messageDigest);
    }
    catch (Exception e) {
      throw new RRException("生成Token失败", e);
    }
  }
}
